Merge pull request #1265 from makidoll/pipewire-linux-volume-catcher

Add PipeWire as option for Linux volume catcher

18 files changed, 825 insertions, 290 deletions

diff --git a/indra/media_plugins/base/media_plugin_base.cpp b/indra/media_plugins/base/media_plugin_base.cpp
index 3c603440df..b21f29ac32 100644
--- a/indra/media_plugins/base/media_plugin_base.cpp
+++ b/indra/media_plugins/base/media_plugin_base.cpp
@@ -183,13 +183,13 @@ bool SymbolGrabber::grabSymbols(std::vector< std::string > const &aDSONames)
         return true;
 
     //attempt to load the shared libraries
-    apr_pool_create(&sSymPADSOMemoryPool, nullptr);
+    apr_pool_create(&sSymDSOMemoryPool, nullptr);
 
     for( std::vector< std::string >::const_iterator itr = aDSONames.begin(); itr != aDSONames.end(); ++itr )
     {
         apr_dso_handle_t *pDSO(NULL);
         std::string strDSO{ *itr };
-        if( APR_SUCCESS == apr_dso_load( &pDSO, strDSO.c_str(), sSymPADSOMemoryPool ))
+        if( APR_SUCCESS == apr_dso_load( &pDSO, strDSO.c_str(), sSymDSOMemoryPool ))
             sLoadedLibraries.push_back( pDSO );
 
         for( auto i = 0; i < gSymbolsToGrab.size(); ++i )
@@ -254,3 +254,50 @@ int WINAPI DllEntryPoint( HINSTANCE hInstance, unsigned long reason, void* param
     return 1;
 }
 #endif
+
+#if LL_LINUX
+pid_t getParentPid( pid_t aPid )
+{
+    std::stringstream strm;
+    strm << "/proc/" << aPid << "/status";
+    std::ifstream in{ strm.str() };
+
+    if( !in.is_open() )
+        return 0;
+
+    pid_t res {0};
+    while( !in.eof() && res == 0 )
+    {
+        std::string line;
+        line.resize( 1024, 0 );
+        in.getline( &line[0], line.length() );	
+
+        auto i = line.find( "PPid:"  );
+        
+        if( i == std::string::npos )
+            continue;
+        
+        char const *pIn = line.c_str() + 5; // Skip over pid;
+        while( *pIn != 0 && isspace( *pIn ) )
+               ++pIn;
+
+        if( *pIn )
+            res = atoll( pIn );
+    }
+     return res;
+}
+
+bool isPluginPid( pid_t aPid )
+{
+    auto myPid = getpid();
+
+    do
+    {
+        if( aPid == myPid )
+            return true;
+        aPid = getParentPid( aPid );
+    } while( aPid > 1 );
+
+    return false;
+}
+#endif
diff --git a/indra/media_plugins/base/media_plugin_base.h b/indra/media_plugins/base/media_plugin_base.h
index d5cb5ac550..a084fc9834 100644
--- a/indra/media_plugins/base/media_plugin_base.h
+++ b/indra/media_plugins/base/media_plugin_base.h
@@ -52,12 +52,19 @@ private:
     std::vector< SymbolToGrab > gSymbolsToGrab;
 
     bool sSymsGrabbed = false;
-    apr_pool_t *sSymPADSOMemoryPool = nullptr;
+    apr_pool_t *sSymDSOMemoryPool = nullptr;
     std::vector<apr_dso_handle_t *> sLoadedLibraries;
 };
 
 extern SymbolGrabber gSymbolGrabber;
-#define LL_GRAB_SYM(REQUIRED, SYMBOL_NAME, RETURN, ...) RETURN (*ll##SYMBOL_NAME)(__VA_ARGS__) = nullptr; size_t gRegistered##SYMBOL_NAME = gSymbolGrabber.registerSymbol( { REQUIRED, #SYMBOL_NAME , (apr_dso_handle_sym_t*)&ll##SYMBOL_NAME} );
+
+// extern SymbolGrabber gSymbolGrabber;
+
+#define LL_GRAB_SYM(SYMBOL_GRABBER, REQUIRED, SYMBOL_NAME, RETURN, ...) \
+    RETURN (*ll##SYMBOL_NAME)(__VA_ARGS__) = nullptr; \
+    size_t gRegistered##SYMBOL_NAME = SYMBOL_GRABBER.registerSymbol( \
+        { REQUIRED, #SYMBOL_NAME , (apr_dso_handle_sym_t*)&ll##SYMBOL_NAME} \
+    );
 
 #endif
 
@@ -153,4 +160,7 @@ int init_media_plugin(
     LLPluginInstance::sendMessageFunction *plugin_send_func,
     void **plugin_user_data);
 
-
+#if LL_LINUX
+pid_t getParentPid(pid_t aPid);
+bool isPluginPid(pid_t aPid);
+#endif
diff --git a/indra/media_plugins/cef/CMakeLists.txt b/indra/media_plugins/cef/CMakeLists.txt
index bbd2eb222a..2c4ccd46d7 100644
--- a/indra/media_plugins/cef/CMakeLists.txt
+++ b/indra/media_plugins/cef/CMakeLists.txt
@@ -33,14 +33,27 @@ if (LINUX)
       message( "Looking for ${PULSE_FILE} ... found")
     endif()
   endforeach()
-  message( "Building with linux volume catcher" )
-  set(LINUX_VOLUME_CATCHER linux_volume_catcher.cpp)
+  
+  include(FindPipeWire)
+  include_directories(SYSTEM ${PIPEWIRE_INCLUDE_DIRS} ${SPA_INCLUDE_DIRS})
+  
+  message( "Building with Linux volume catcher for PipeWire and PulseAudio" )
+
+  list(APPEND media_plugin_cef_HEADER_FILES
+    linux/volume_catcher_linux.h
+  )
+
+  set(LINUX_VOLUME_CATCHER 
+    linux/volume_catcher_linux.cpp 
+    linux/volume_catcher_pulseaudio.cpp
+    linux/volume_catcher_pipewire.cpp 
+  )
 
   list(APPEND media_plugin_cef_SOURCE_FILES ${LINUX_VOLUME_CATCHER})
   set(CMAKE_SHARED_LINKER_FLAGS  "-Wl,--build-id -Wl,-rpath,'$ORIGIN:$ORIGIN/../../lib'")
   list(APPEND media_plugin_cef_LINK_LIBRARIES llwindow )
 elseif (DARWIN)
-  list(APPEND media_plugin_cef_SOURCE_FILES mac_volume_catcher_null.cpp)
+  list(APPEND media_plugin_cef_SOURCE_FILES volume_catcher_null.cpp)
   find_library(CORESERVICES_LIBRARY CoreServices)
   find_library(AUDIOUNIT_LIBRARY AudioUnit)
   set( media_plugin_cef_LINK_LIBRARIES
diff --git a/indra/media_plugins/cef/linux/volume_catcher_linux.cpp b/indra/media_plugins/cef/linux/volume_catcher_linux.cpp
new file mode 100644
index 0000000000..7d33242063
--- /dev/null
+++ b/indra/media_plugins/cef/linux/volume_catcher_linux.cpp
@@ -0,0 +1,78 @@
+/**
+ * @file volume_catcher.cpp
+ * @brief Linux volume catcher which will pick an implementation to use
+ *
+ * @cond
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ * @endcond
+ */
+
+#include "volume_catcher_linux.h"
+
+VolumeCatcher::VolumeCatcher()
+{
+}
+
+void VolumeCatcher::onEnablePipeWireVolumeCatcher(bool enable)
+{
+    if (pimpl != nullptr)
+        return;
+
+    if (enable)
+    {
+        LL_DEBUGS() << "volume catcher using pipewire" << LL_ENDL;
+        pimpl = new VolumeCatcherPipeWire();
+    }
+    else
+    {
+        LL_DEBUGS() << "volume catcher using pulseaudio" << LL_ENDL;
+        pimpl = new VolumeCatcherPulseAudio();
+    }
+}
+
+VolumeCatcher::~VolumeCatcher()
+{
+    if (pimpl != nullptr)
+    {
+        delete pimpl;
+        pimpl = nullptr;
+    }
+}
+
+void VolumeCatcher::setVolume(F32 volume)
+{
+    if (pimpl != nullptr) {
+        pimpl->setVolume(volume);
+    }
+}
+
+void VolumeCatcher::setPan(F32 pan)
+{
+    if (pimpl != nullptr)
+        pimpl->setPan(pan);
+}
+
+void VolumeCatcher::pump()
+{
+    if (pimpl != nullptr)
+        pimpl->pump();
+}
diff --git a/indra/media_plugins/cef/linux/volume_catcher_linux.h b/indra/media_plugins/cef/linux/volume_catcher_linux.h
new file mode 100644
index 0000000000..505f9ffb31
--- /dev/null
+++ b/indra/media_plugins/cef/linux/volume_catcher_linux.h
@@ -0,0 +1,149 @@
+/**
+ * @file volume_catcher_impl.h
+ * @brief
+ *
+ * @cond
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ * @endcond
+ */
+
+#ifndef VOLUME_CATCHER_LINUX_H
+#define VOLUME_CATCHER_LINUX_H
+
+#include "linden_common.h"
+
+#include "../volume_catcher.h"
+
+#include <unordered_set>
+#include <mutex>
+
+extern "C" {
+// There's no special reason why we want the *glib* PA mainloop, but the generic polling implementation seems broken.
+#include <pulse/glib-mainloop.h>
+#include <pulse/context.h>
+
+#include <pipewire/pipewire.h>
+
+#include "apr_pools.h"
+#include "apr_dso.h"
+}
+
+#include "media_plugin_base.h"
+
+class VolumeCatcherImpl
+{
+public:
+    virtual ~VolumeCatcherImpl() = default;
+
+    virtual void setVolume(F32 volume) = 0; // 0.0 - 1.0
+
+    // Set the left-right pan of audio sources
+    // where -1.0 = left, 0 = center, and 1.0 = right
+    virtual void setPan(F32 pan) = 0;
+
+    virtual void pump() = 0; // call this at least a few times a second if you can - it affects how quickly we can 'catch' a new audio source and adjust its volume
+};
+
+class VolumeCatcherPulseAudio : public VolumeCatcherImpl
+{
+public:
+    VolumeCatcherPulseAudio();
+    ~VolumeCatcherPulseAudio();
+
+    void setVolume(F32 volume);
+    void setPan(F32 pan);
+    void pump();
+
+    // for internal use - can't be private because used from our C callbacks
+
+    bool loadsyms(std::string pa_dso_name);
+    void init();
+    void cleanup();
+
+    void update_all_volumes(F32 volume);
+    void update_index_volume(U32 index, F32 volume);
+    void connected_okay();
+
+    std::set<U32> mSinkInputIndices;
+    std::map<U32,U32> mSinkInputNumChannels;
+    F32 mDesiredVolume;
+    pa_glib_mainloop *mMainloop;
+    pa_context *mPAContext;
+    bool mConnected;
+    bool mGotSyms;
+};
+
+class VolumeCatcherPipeWire : public VolumeCatcherImpl
+{
+public:
+    VolumeCatcherPipeWire();
+    ~VolumeCatcherPipeWire();
+
+    bool loadsyms(std::string pw_dso_name);
+    void init();
+    void cleanup();
+
+    // some of these should be private
+
+    void lock();
+    void unlock();
+
+    void setVolume(F32 volume);
+    void setPan(F32 pan);
+    void pump();
+
+    void handleRegistryEventGlobal(
+        uint32_t id, uint32_t permissions, const char* type,
+        uint32_t version, const struct spa_dict* props
+    );
+
+    class ChildNode
+    {
+    public:
+        bool mActive = false;
+
+        pw_proxy* mProxy = nullptr;
+        spa_hook mNodeListener {};
+        spa_hook mProxyListener {};
+        VolumeCatcherPipeWire* mImpl = nullptr;
+
+        void updateVolume();
+        void destroy();
+    };
+
+    bool mGotSyms = false;
+
+    F32 mVolume = 1.0f; // max by default
+    // F32 mPan = 0.0f; // center
+
+    pw_thread_loop* mThreadLoop = nullptr;
+    pw_context* mContext = nullptr;
+    pw_core* mCore = nullptr;
+    pw_registry* mRegistry = nullptr;
+    spa_hook mRegistryListener;
+
+    std::unordered_set<ChildNode*> mChildNodes;
+    std::mutex mChildNodesMutex;
+    std::mutex mCleanupMutex;
+};
+
+#endif // VOLUME_CATCHER_LINUX_H
diff --git a/indra/media_plugins/cef/linux/volume_catcher_pipewire.cpp b/indra/media_plugins/cef/linux/volume_catcher_pipewire.cpp
new file mode 100755
index 0000000000..27fea547c9
--- /dev/null
+++ b/indra/media_plugins/cef/linux/volume_catcher_pipewire.cpp
@@ -0,0 +1,333 @@
+/** 
+ * @file volume_catcher_pipewire.cpp
+ * @brief A Linux-specific, PipeWire-specific hack to detect and volume-adjust new audio sources
+ *
+ * @cond
+ * $LicenseInfo:firstyear=2010&license=viewerlgpl$
+ * Second Life Viewer Source Code
+ * Copyright (C) 2010, Linden Research, Inc.
+ * 
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ * 
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ * 
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * 
+ * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
+ * $/LicenseInfo$
+ * @endcond
+ */
+
+/*
+  The high-level design is as follows:
+  1) Connect to the PipeWire daemon
+  2) Find all existing and new audio nodes
+  3) Examine PID and parent PID's to see if it belongs to our process
+  4) If so, tell PipeWire to adjust the volume of that node
+  5) Keep a list of all audio nodes and adjust when we setVolume()
+ */
+
+#include "linden_common.h"
+
+#include "volume_catcher_linux.h"
+
+extern "C" {
+#include <spa/pod/builder.h>
+#include <spa/param/props.h>
+}
+
+SymbolGrabber pwSymbolGrabber;
+
+#include "volume_catcher_pipewire_syms.inc"
+
+////////////////////////////////////////////////////
+
+VolumeCatcherPipeWire::VolumeCatcherPipeWire()
+{
+    init();
+}
+
+VolumeCatcherPipeWire::~VolumeCatcherPipeWire()
+{
+    cleanup();
+}
+
+static void registryEventGlobal(
+    void *data, uint32_t id, uint32_t permissions, const char *type,
+    uint32_t version, const struct spa_dict *props)
+{
+    static_cast<VolumeCatcherPipeWire*>(data)->handleRegistryEventGlobal(
+        id, permissions, type, version, props
+    );
+}
+
+static const struct pw_registry_events REGISTRY_EVENTS = {
+    .version = PW_VERSION_REGISTRY_EVENTS,
+    .global = registryEventGlobal,
+};
+
+bool VolumeCatcherPipeWire::loadsyms(std::string pw_dso_name)
+{
+    return pwSymbolGrabber.grabSymbols({ pw_dso_name });
+}
+
+void VolumeCatcherPipeWire::init()
+{
+    LL_DEBUGS() << "init" << LL_ENDL;
+
+    mGotSyms = loadsyms("libpipewire-0.3.so.0");
+
+    if (!mGotSyms)
+        return;
+
+    LL_DEBUGS() << "successfully got symbols" << LL_ENDL;
+
+    llpw_init(nullptr, nullptr);
+
+    mThreadLoop = llpw_thread_loop_new("SL Plugin Volume Adjuster", nullptr);
+
+    if (!mThreadLoop)
+        return;
+
+    // i dont think we need to lock this early
+    // std::lock_guard pwLock(*this);
+
+    mContext = llpw_context_new(
+        llpw_thread_loop_get_loop(mThreadLoop), nullptr, 0
+    );
+
+    if (!mContext)
+        return;
+
+    mCore = llpw_context_connect(mContext, nullptr, 0);
+
+    if (!mCore)
+        return;
+
+    mRegistry = pw_core_get_registry(mCore, PW_VERSION_REGISTRY, 0);
+
+    LL_DEBUGS() << "pw_core_get_registry: " <<  (mRegistry?"success":"nullptr") << LL_ENDL;
+
+    spa_zero(mRegistryListener);
+
+    pw_registry_add_listener(
+        mRegistry, &mRegistryListener, &REGISTRY_EVENTS, this
+    );
+
+    llpw_thread_loop_start(mThreadLoop);
+
+    LL_DEBUGS() << "thread loop started" << LL_ENDL;
+}
+
+void VolumeCatcherPipeWire::cleanup()
+{
+    {
+        std::unique_lock childNodesLock(mChildNodesMutex);
+        for (auto *childNode: mChildNodes)
+            childNode->destroy();
+
+        mChildNodes.clear();
+    }
+
+    {
+        std::unique_lock pwLock(mCleanupMutex);
+        if (mRegistry)
+            llpw_proxy_destroy((struct pw_proxy *) mRegistry);
+
+        spa_zero(mRegistryListener);
+
+        if (mCore)
+            llpw_core_disconnect(mCore);
+        if (mContext)
+            llpw_context_destroy(mContext);
+    }
+
+    if (!mThreadLoop)
+        return;
+
+    llpw_thread_loop_stop(mThreadLoop);
+    llpw_thread_loop_destroy(mThreadLoop);
+
+    LL_DEBUGS() << "cleanup done" << LL_ENDL;
+}
+
+void VolumeCatcherPipeWire::lock()
+{
+    if (!mThreadLoop)
+        return;
+
+    llpw_thread_loop_lock(mThreadLoop);
+}
+
+void VolumeCatcherPipeWire::unlock()
+{
+    if (!mThreadLoop)
+        return;
+
+    llpw_thread_loop_unlock(mThreadLoop);
+}
+
+const uint32_t channels = 1;
+const float resetVolumes[channels] = { 1.0f };
+
+void VolumeCatcherPipeWire::ChildNode::updateVolume()
+{
+    if (!mActive)
+        return;
+
+    F32 volume = std::clamp(mImpl->mVolume, 0.0f, 1.0f);
+
+    const float volumes[channels] = { volume };
+
+    uint8_t buffer[512];
+
+    spa_pod_builder builder;
+    spa_pod_builder_init(&builder, buffer, sizeof(buffer));
+
+    spa_pod_frame frame;
+    spa_pod_builder_push_object(&builder, &frame, SPA_TYPE_OBJECT_Props, SPA_PARAM_Props);
+
+    // resets system-wide memorized volume for chromium (not google chrome) to 100%
+    spa_pod_builder_prop(&builder, SPA_PROP_channelVolumes, 0);
+    spa_pod_builder_array(&builder, sizeof(float), SPA_TYPE_Float, channels, resetVolumes);
+
+    // sets temporary volume
+    spa_pod_builder_prop(&builder, SPA_PROP_softVolumes, 0);
+    spa_pod_builder_array(&builder, sizeof(float), SPA_TYPE_Float, channels, volumes);
+
+    spa_pod* pod = static_cast<spa_pod*>(spa_pod_builder_pop(&builder, &frame));
+
+    {
+        std::lock_guard pwLock(*mImpl);
+        pw_node_set_param(mProxy, SPA_PARAM_Props, 0, pod);
+    }
+}
+
+void VolumeCatcherPipeWire::ChildNode::destroy()
+{
+    if (!mActive)
+        return;
+
+    mActive = false;
+
+    {
+        std::unique_lock childNodesLock(mImpl->mChildNodesMutex);
+        mImpl->mChildNodes.erase(this);
+    }
+
+    spa_hook_remove(&mNodeListener);
+    spa_hook_remove(&mProxyListener);
+
+    {
+        std::lock_guard pwLock(*mImpl);
+        llpw_proxy_destroy(mProxy);
+    }
+}
+
+static void nodeEventInfo(void* data, const struct pw_node_info* info)
+{
+    const char* processId = spa_dict_lookup(info->props, PW_KEY_APP_PROCESS_ID);
+
+    if (processId == nullptr)
+        return;
+
+    pid_t pid = atoll(processId);
+
+    if (!isPluginPid(pid))
+        return;
+
+    const char* appName = spa_dict_lookup(info->props, PW_KEY_APP_NAME);
+    LL_DEBUGS() << "got app: " << appName << LL_ENDL;
+
+    auto* const childNode = static_cast<VolumeCatcherPipeWire::ChildNode*>(data);
+    LL_DEBUGS() << "init volume: " << childNode->mImpl->mVolume  << LL_ENDL;
+
+    childNode->updateVolume();
+
+    {
+        std::lock_guard childNodesLock(childNode->mImpl->mChildNodesMutex);
+        childNode->mImpl->mChildNodes.insert(childNode);
+    }
+}
+
+static const struct pw_node_events NODE_EVENTS = {
+    .version = PW_VERSION_CLIENT_EVENTS,
+    .info = nodeEventInfo,
+};
+
+static void proxyEventDestroy(void* data)
+{
+    auto* const childNode = static_cast<VolumeCatcherPipeWire::ChildNode*>(data);
+    childNode->destroy();
+}
+
+static void proxyEventRemoved(void* data)
+{
+    auto* const childNode = static_cast<VolumeCatcherPipeWire::ChildNode*>(data);
+    childNode->destroy();
+}
+
+static const struct pw_proxy_events PROXY_EVENTS = {
+    .version = PW_VERSION_PROXY_EVENTS,
+    .destroy = proxyEventDestroy,
+    .removed = proxyEventRemoved,
+};
+
+void VolumeCatcherPipeWire::handleRegistryEventGlobal(
+    uint32_t id, uint32_t permissions, const char *type, uint32_t version,
+    const struct spa_dict *props)
+{
+    if (props == nullptr  || type == nullptr || strcmp(type, PW_TYPE_INTERFACE_Node) != 0)
+        return;
+
+    const char* mediaClass = spa_dict_lookup(props, PW_KEY_MEDIA_CLASS);
+
+    if (mediaClass == nullptr || strcmp(mediaClass, "Stream/Output/Audio") != 0)
+        return;
+
+    pw_proxy* proxy = static_cast<pw_proxy*>(
+        pw_registry_bind(mRegistry, id, type, PW_VERSION_CLIENT, sizeof(ChildNode))
+    );
+
+    auto* const childNode = static_cast<ChildNode*>(llpw_proxy_get_user_data(proxy));
+
+    childNode->mActive = true;
+    childNode->mProxy = proxy;
+    childNode->mImpl = this;
+
+    pw_node_add_listener(proxy, &childNode->mNodeListener, &NODE_EVENTS, childNode);
+    llpw_proxy_add_listener(proxy, &childNode->mProxyListener, &PROXY_EVENTS, childNode);
+}
+
+void VolumeCatcherPipeWire::setVolume(F32 volume)
+{
+    LL_DEBUGS() << "setting volume to: " << volume << LL_ENDL;
+
+    mVolume = volume;
+
+    {
+        std::unique_lock childNodeslock(mChildNodesMutex);
+        std::unordered_set<ChildNode *> copyOfChildNodes(mChildNodes);
+
+        LL_DEBUGS() << "found " << copyOfChildNodes.size() << " child nodes" << LL_ENDL;
+
+        for (auto* childNode : copyOfChildNodes)
+            childNode->updateVolume();
+    }
+}
+
+void VolumeCatcherPipeWire::setPan(F32 pan)
+{
+}
+
+void VolumeCatcherPipeWire::pump()
+{
+}
diff --git a/indra/media_plugins/cef/linux/volume_catcher_pipewire_syms.inc b/indra/media_plugins/cef/linux/volume_catcher_pipewire_syms.inc
new file mode 100644
index 0000000000..dbc0f5f169
--- /dev/null
+++ b/indra/media_plugins/cef/linux/volume_catcher_pipewire_syms.inc
@@ -0,0 +1,26 @@
+#define G pwSymbolGrabber
+
+// required symbols to grab
+LL_GRAB_SYM(G, true, pw_init, void, int *argc, char **argv[]);
+// LL_GRAB_SYM(G, true, pw_main_loop_new, struct pw_main_loop *, const struct spa_dict *props);
+// LL_GRAB_SYM(G, true, pw_main_loop_get_loop, struct pw_loop *, struct pw_main_loop *loop);
+// LL_GRAB_SYM(G, true, pw_main_loop_destroy, void, struct pw_main_loop *loop);
+// LL_GRAB_SYM(G, true, pw_main_loop_run, void, struct pw_main_loop *loop);
+LL_GRAB_SYM(G, true, pw_context_new, struct pw_context *, struct pw_loop *main_loop, struct pw_properties *props, size_t user_data_size);
+LL_GRAB_SYM(G, true, pw_context_destroy, void, struct pw_context *context);
+LL_GRAB_SYM(G, true, pw_context_connect, struct pw_core *, struct pw_context *context, struct pw_properties *properties, size_t user_data_size);
+LL_GRAB_SYM(G, true, pw_thread_loop_new, struct pw_thread_loop *, const char *name, const struct spa_dict *props);
+LL_GRAB_SYM(G, true, pw_thread_loop_destroy, void, struct pw_thread_loop *loop);
+LL_GRAB_SYM(G, true, pw_thread_loop_get_loop, struct pw_loop *, struct pw_thread_loop *loop);
+LL_GRAB_SYM(G, true, pw_thread_loop_start, int, struct pw_thread_loop *loop);
+LL_GRAB_SYM(G, true, pw_thread_loop_stop, void, struct pw_thread_loop *loop);
+LL_GRAB_SYM(G, true, pw_thread_loop_lock, void, struct pw_thread_loop *loop);
+LL_GRAB_SYM(G, true, pw_thread_loop_unlock, void, struct pw_thread_loop *loop);
+LL_GRAB_SYM(G, true, pw_proxy_add_listener, void, struct pw_proxy *proxy, struct spa_hook *listener, const struct pw_proxy_events *events, void *data);
+LL_GRAB_SYM(G, true, pw_proxy_destroy, void, struct pw_proxy *proxy);
+LL_GRAB_SYM(G, true, pw_proxy_get_user_data, void *, struct pw_proxy *proxy);
+LL_GRAB_SYM(G, true, pw_core_disconnect, int, struct pw_core *core);
+
+// optional symbols to grab
+
+#undef G
diff --git a/indra/media_plugins/cef/linux_volume_catcher.cpp b/indra/media_plugins/cef/linux/volume_catcher_pulseaudio.cpp
index 982b79f5b3..9417c49d38 100755
--- a/indra/media_plugins/cef/linux_volume_catcher.cpp
+++ b/indra/media_plugins/cef/linux/volume_catcher_pulseaudio.cpp
@@ -1,26 +1,26 @@
-/**
- * @file linux_volume_catcher.cpp
+/** 
+ * @file volume_catcher_pulseaudio.cpp
  * @brief A Linux-specific, PulseAudio-specific hack to detect and volume-adjust new audio sources
  *
  * @cond
  * $LicenseInfo:firstyear=2010&license=viewerlgpl$
  * Second Life Viewer Source Code
  * Copyright (C) 2010, Linden Research, Inc.
- *
+ * 
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation;
  * version 2.1 of the License only.
- *
+ * 
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
- *
+ * 
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
- *
+ * 
  * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
  * $/LicenseInfo$
  * @endcond
@@ -37,29 +37,22 @@
 
 #include "linden_common.h"
 
-#include "volume_catcher.h"
-#include <set>
-#include <map>
-#include <iostream>
+#include "volume_catcher_linux.h"
+
 extern "C" {
 #include <glib.h>
 #include <glib-object.h>
 
 #include <pulse/introspect.h>
-#include <pulse/context.h>
-#include <pulse/subscribe.h>
-#include <pulse/glib-mainloop.h> // There's no special reason why we want the *glib* PA mainloop, but the generic polling implementation seems broken.
 
-#include "apr_pools.h"
-#include "apr_dso.h"
+#include <pulse/subscribe.h>
 }
 
-#include "media_plugin_base.h"
+SymbolGrabber paSymbolGrabber;
 
-SymbolGrabber gSymbolGrabber;
+#include "volume_catcher_pulseaudio_syms.inc"
+#include "volume_catcher_pulseaudio_glib_syms.inc"
 
-#include "linux_volume_catcher_pa_syms.inc"
-#include "linux_volume_catcher_paglib_syms.inc"
 ////////////////////////////////////////////////////
 
 // PulseAudio requires a chain of callbacks with C linkage
@@ -69,35 +62,7 @@ extern "C" {
     void callback_context_state(pa_context *context, void *userdata);
 }
 
-class VolumeCatcherImpl
-{
-public:
-    VolumeCatcherImpl();
-    ~VolumeCatcherImpl();
-
-    void setVolume(F32 volume);
-    void pump(void);
-
-    // for internal use - can't be private because used from our C callbacks
-
-    bool loadsyms(std::string pulse_dso_name);
-    void init();
-    void cleanup();
-
-    void update_all_volumes(F32 volume);
-    void update_index_volume(U32 index, F32 volume);
-    void connected_okay();
-
-    std::set<U32> mSinkInputIndices;
-    std::map<U32,U32> mSinkInputNumChannels;
-    F32 mDesiredVolume;
-    pa_glib_mainloop *mMainloop;
-    pa_context *mPAContext;
-    bool mConnected;
-    bool mGotSyms;
-};
-
-VolumeCatcherImpl::VolumeCatcherImpl()
+VolumeCatcherPulseAudio::VolumeCatcherPulseAudio()
     : mDesiredVolume(0.0f),
       mMainloop(nullptr),
       mPAContext(nullptr),
@@ -107,18 +72,17 @@ VolumeCatcherImpl::VolumeCatcherImpl()
     init();
 }
 
-VolumeCatcherImpl::~VolumeCatcherImpl()
+VolumeCatcherPulseAudio::~VolumeCatcherPulseAudio()
 {
     cleanup();
 }
 
-bool VolumeCatcherImpl::loadsyms(std::string pulse_dso_name)
+bool VolumeCatcherPulseAudio::loadsyms(std::string pulse_dso_name)
 {
-    //return grab_pa_syms({pulse_dso_name});
-    return gSymbolGrabber.grabSymbols( { pulse_dso_name }) ;
+    return paSymbolGrabber.grabSymbols({ pulse_dso_name });
 }
 
-void VolumeCatcherImpl::init()
+void VolumeCatcherPulseAudio::init()
 {
     // try to be as defensive as possible because PA's interface is a
     // bit fragile and (for our purposes) we'd rather simply not function
@@ -129,7 +93,12 @@ void VolumeCatcherImpl::init()
     // probably be loaded separately.  Our Linux DSO framework needs refactoring,
     // we do this sort of thing a lot with practically identical logic...
     mGotSyms = loadsyms("libpulse-mainloop-glib.so.0");
-    if (!mGotSyms) return;
+
+    if (!mGotSyms)
+        mGotSyms = loadsyms("libpulse.so.0");
+
+    if (!mGotSyms)
+        return;
 
     mMainloop = llpa_glib_mainloop_new(g_main_context_default());
 
@@ -175,7 +144,7 @@ void VolumeCatcherImpl::init()
     }
 }
 
-void VolumeCatcherImpl::cleanup()
+void VolumeCatcherPulseAudio::cleanup()
 {
     mConnected = false;
 
@@ -193,11 +162,12 @@ void VolumeCatcherImpl::cleanup()
     mMainloop = nullptr;
 }
 
-void VolumeCatcherImpl::setVolume(F32 volume)
+void VolumeCatcherPulseAudio::setVolume(F32 volume)
 {
     mDesiredVolume = volume;
 
-    if (!mGotSyms) return;
+    if (!mGotSyms)
+        return;
 
     if (mConnected && mPAContext)
     {
@@ -207,13 +177,17 @@ void VolumeCatcherImpl::setVolume(F32 volume)
     pump();
 }
 
-void VolumeCatcherImpl::pump()
+void VolumeCatcherPulseAudio::setPan(F32 pan)
+{
+}
+
+void VolumeCatcherPulseAudio::pump()
 {
     gboolean may_block = FALSE;
     g_main_context_iteration(g_main_context_default(), may_block);
 }
 
-void VolumeCatcherImpl::connected_okay()
+void VolumeCatcherPulseAudio::connected_okay()
 {
     pa_operation *op;
 
@@ -237,7 +211,7 @@ void VolumeCatcherImpl::connected_okay()
     }
 }
 
-void VolumeCatcherImpl::update_all_volumes(F32 volume)
+void VolumeCatcherPulseAudio::update_all_volumes(F32 volume)
 {
     for (std::set<U32>::iterator it = mSinkInputIndices.begin();
          it != mSinkInputIndices.end(); ++it)
@@ -246,7 +220,7 @@ void VolumeCatcherImpl::update_all_volumes(F32 volume)
     }
 }
 
-void VolumeCatcherImpl::update_index_volume(U32 index, F32 volume)
+void VolumeCatcherPulseAudio::update_index_volume(U32 index, F32 volume)
 {
     static pa_cvolume cvol;
     llpa_cvolume_set(&cvol, mSinkInputNumChannels[index],
@@ -263,55 +237,9 @@ void VolumeCatcherImpl::update_index_volume(U32 index, F32 volume)
         llpa_operation_unref(op);
 }
 
-pid_t getParentPid( pid_t aPid )
-{
-    std::stringstream strm;
-    strm << "/proc/" << aPid << "/status";
-    std::ifstream in{ strm.str() };
-
-    if( !in.is_open() )
-        return 0;
-
-    pid_t res {0};
-    while( !in.eof() && res == 0 )
-    {
-        std::string line;
-        line.resize( 1024, 0 );
-        in.getline( &line[0], line.length() );
-
-        auto i = line.find( "PPid:"  );
-
-        if( i == std::string::npos )
-            continue;
-
-        char const *pIn = line.c_str() + 5; // Skip over pid;
-        while( *pIn != 0 && isspace( *pIn ) )
-               ++pIn;
-
-        if( *pIn )
-            res = atoll( pIn );
-    }
-    return res;
-}
-
-
-bool isPluginPid( pid_t aPid )
-{
-    auto myPid = getpid();
-
-    do
-    {
-        if( aPid == myPid )
-            return true;
-        aPid = getParentPid( aPid );
-    } while( aPid > 1 );
-
-    return false;
-}
-
 void callback_discovered_sinkinput(pa_context *context, const pa_sink_input_info *sii, int eol, void *userdata)
 {
-    VolumeCatcherImpl *impl = dynamic_cast<VolumeCatcherImpl*>((VolumeCatcherImpl*)userdata);
+    VolumeCatcherPulseAudio *impl = dynamic_cast<VolumeCatcherPulseAudio*>((VolumeCatcherPulseAudio*)userdata);
     llassert(impl);
 
     if (0 == eol)
@@ -341,7 +269,7 @@ void callback_discovered_sinkinput(pa_context *context, const pa_sink_input_info
 
 void callback_subscription_alert(pa_context *context, pa_subscription_event_type_t t, uint32_t index, void *userdata)
 {
-    VolumeCatcherImpl *impl = dynamic_cast<VolumeCatcherImpl*>((VolumeCatcherImpl*)userdata);
+    VolumeCatcherPulseAudio *impl = dynamic_cast<VolumeCatcherPulseAudio*>((VolumeCatcherPulseAudio*)userdata);
     llassert(impl);
 
     switch (t & PA_SUBSCRIPTION_EVENT_FACILITY_MASK)
@@ -374,7 +302,7 @@ void callback_subscription_alert(pa_context *context, pa_subscription_event_type
 
 void callback_context_state(pa_context *context, void *userdata)
 {
-    VolumeCatcherImpl *impl = dynamic_cast<VolumeCatcherImpl*>((VolumeCatcherImpl*)userdata);
+    VolumeCatcherPulseAudio *impl = dynamic_cast<VolumeCatcherPulseAudio*>((VolumeCatcherPulseAudio*)userdata);
     llassert(impl);
 
     switch (llpa_context_get_state(context))
@@ -392,33 +320,3 @@ void callback_context_state(pa_context *context, void *userdata)
     default:;
     }
 }
-
-/////////////////////////////////////////////////////
-
-VolumeCatcher::VolumeCatcher()
-{
-    pimpl = new VolumeCatcherImpl();
-}
-
-VolumeCatcher::~VolumeCatcher()
-{
-    delete pimpl;
-    pimpl = nullptr;
-}
-
-void VolumeCatcher::setVolume(F32 volume)
-{
-    llassert(pimpl);
-    pimpl->setVolume(volume);
-}
-
-void VolumeCatcher::setPan(F32 pan)
-{
-    // TODO: implement this (if possible)
-}
-
-void VolumeCatcher::pump()
-{
-    llassert(pimpl);
-    pimpl->pump();
-}
diff --git a/indra/media_plugins/cef/linux/volume_catcher_pulseaudio_glib_syms.inc b/indra/media_plugins/cef/linux/volume_catcher_pulseaudio_glib_syms.inc
new file mode 100755
index 0000000000..e9b7196e51
--- /dev/null
+++ b/indra/media_plugins/cef/linux/volume_catcher_pulseaudio_glib_syms.inc
@@ -0,0 +1,10 @@
+#define G paSymbolGrabber
+
+// required symbols to grab
+LL_GRAB_SYM(G, true, pa_glib_mainloop_free, void, pa_glib_mainloop* g)
+LL_GRAB_SYM(G, true, pa_glib_mainloop_get_api, pa_mainloop_api*, pa_glib_mainloop* g)
+LL_GRAB_SYM(G, true, pa_glib_mainloop_new, pa_glib_mainloop *, GMainContext *c)
+
+// optional symbols to grab
+
+#undef G
diff --git a/indra/media_plugins/cef/linux/volume_catcher_pulseaudio_syms.inc b/indra/media_plugins/cef/linux/volume_catcher_pulseaudio_syms.inc
new file mode 100755
index 0000000000..4859a34405
--- /dev/null
+++ b/indra/media_plugins/cef/linux/volume_catcher_pulseaudio_syms.inc
@@ -0,0 +1,29 @@
+#define G paSymbolGrabber
+
+// required symbols to grab
+LL_GRAB_SYM(G, true, pa_context_connect, int, pa_context *c, const char *server, pa_context_flags_t flags, const pa_spawn_api *api)
+LL_GRAB_SYM(G, true, pa_context_disconnect, void, pa_context *c)
+LL_GRAB_SYM(G, true, pa_context_get_sink_input_info, pa_operation*, pa_context *c, uint32_t idx, pa_sink_input_info_cb_t cb, void *userdata)
+LL_GRAB_SYM(G, true, pa_context_get_sink_input_info_list, pa_operation*, pa_context *c, pa_sink_input_info_cb_t cb, void *userdata)
+LL_GRAB_SYM(G, true, pa_context_get_state, pa_context_state_t, pa_context *c)
+LL_GRAB_SYM(G, true, pa_context_new_with_proplist, pa_context*, pa_mainloop_api *mainloop, const char *name, pa_proplist *proplist)
+LL_GRAB_SYM(G, true, pa_context_set_sink_input_volume, pa_operation*, pa_context *c, uint32_t idx, const pa_cvolume *volume, pa_context_success_cb_t cb, void *userdata)
+LL_GRAB_SYM(G, true, pa_context_set_state_callback, void, pa_context *c, pa_context_notify_cb_t cb, void *userdata)
+LL_GRAB_SYM(G, true, pa_context_set_subscribe_callback, void, pa_context *c, pa_context_subscribe_cb_t cb, void *userdata)
+LL_GRAB_SYM(G, true, pa_context_subscribe, pa_operation*, pa_context *c, pa_subscription_mask_t m, pa_context_success_cb_t cb, void *userdata)
+LL_GRAB_SYM(G, true, pa_context_unref, void, pa_context *c)
+LL_GRAB_SYM(G, true, pa_cvolume_set, pa_cvolume*, pa_cvolume *a, unsigned channels, pa_volume_t v)
+LL_GRAB_SYM(G, true, pa_operation_unref, void, pa_operation *o)
+LL_GRAB_SYM(G, true, pa_proplist_free, void, pa_proplist* p)
+LL_GRAB_SYM(G, true, pa_proplist_gets, const char*, pa_proplist *p, const char *key)
+LL_GRAB_SYM(G, true, pa_proplist_new, pa_proplist*, void)
+LL_GRAB_SYM(G, true, pa_proplist_sets, int, pa_proplist *p, const char *key, const char *value)
+LL_GRAB_SYM(G, true, pa_sw_volume_from_linear, pa_volume_t, double v)
+// LL_GRAB_SYM(G, true, pa_mainloop_free, void, pa_mainloop *m)
+// LL_GRAB_SYM(G, true, pa_mainloop_get_api, pa_mainloop_api *, pa_mainloop *m)
+// LL_GRAB_SYM(G, true, pa_mainloop_iterate, int, pa_mainloop *m, int block, int *retval)
+// LL_GRAB_SYM(G, true, pa_mainloop_new, pa_mainloop *, void)
+
+// optional symbols to grab
+
+#undef G
diff --git a/indra/media_plugins/cef/linux_volume_catcher_pa_syms.inc b/indra/media_plugins/cef/linux_volume_catcher_pa_syms.inc
deleted file mode 100755
index 4533362e61..0000000000
--- a/indra/media_plugins/cef/linux_volume_catcher_pa_syms.inc
+++ /dev/null
@@ -1,21 +0,0 @@
-// required symbols to grab
-LL_GRAB_SYM(true, pa_context_connect, int, pa_context *c, const char *server, pa_context_flags_t flags, const pa_spawn_api *api)
-LL_GRAB_SYM(true, pa_context_disconnect, void, pa_context *c)
-LL_GRAB_SYM(true, pa_context_get_sink_input_info, pa_operation*, pa_context *c, uint32_t idx, pa_sink_input_info_cb_t cb, void *userdata)
-LL_GRAB_SYM(true, pa_context_get_sink_input_info_list, pa_operation*, pa_context *c, pa_sink_input_info_cb_t cb, void *userdata)
-LL_GRAB_SYM(true, pa_context_get_state, pa_context_state_t, pa_context *c)
-LL_GRAB_SYM(true, pa_context_new_with_proplist, pa_context*, pa_mainloop_api *mainloop, const char *name, pa_proplist *proplist)
-LL_GRAB_SYM(true, pa_context_set_sink_input_volume, pa_operation*, pa_context *c, uint32_t idx, const pa_cvolume *volume, pa_context_success_cb_t cb, void *userdata)
-LL_GRAB_SYM(true, pa_context_set_state_callback, void, pa_context *c, pa_context_notify_cb_t cb, void *userdata)
-LL_GRAB_SYM(true, pa_context_set_subscribe_callback, void, pa_context *c, pa_context_subscribe_cb_t cb, void *userdata)
-LL_GRAB_SYM(true, pa_context_subscribe, pa_operation*, pa_context *c, pa_subscription_mask_t m, pa_context_success_cb_t cb, void *userdata)
-LL_GRAB_SYM(true, pa_context_unref, void, pa_context *c)
-LL_GRAB_SYM(true, pa_cvolume_set, pa_cvolume*, pa_cvolume *a, unsigned channels, pa_volume_t v)
-LL_GRAB_SYM(true, pa_operation_unref, void, pa_operation *o)
-LL_GRAB_SYM(true, pa_proplist_free, void, pa_proplist* p)
-LL_GRAB_SYM(true, pa_proplist_gets, const char*, pa_proplist *p, const char *key)
-LL_GRAB_SYM(true, pa_proplist_new, pa_proplist*, void)
-LL_GRAB_SYM(true, pa_proplist_sets, int, pa_proplist *p, const char *key, const char *value)
-LL_GRAB_SYM(true, pa_sw_volume_from_linear, pa_volume_t, double v)
-
-// optional symbols to grab
diff --git a/indra/media_plugins/cef/linux_volume_catcher_paglib_syms.inc b/indra/media_plugins/cef/linux_volume_catcher_paglib_syms.inc
deleted file mode 100755
index 5fba60c188..0000000000
--- a/indra/media_plugins/cef/linux_volume_catcher_paglib_syms.inc
+++ /dev/null
@@ -1,6 +0,0 @@
-// required symbols to grab
-LL_GRAB_SYM(true, pa_glib_mainloop_free, void, pa_glib_mainloop* g)
-LL_GRAB_SYM(true, pa_glib_mainloop_get_api, pa_mainloop_api*, pa_glib_mainloop* g)
-LL_GRAB_SYM(true, pa_glib_mainloop_new, pa_glib_mainloop *, GMainContext *c)
-
-// optional symbols to grab
diff --git a/indra/media_plugins/cef/media_plugin_cef.cpp b/indra/media_plugins/cef/media_plugin_cef.cpp
index c1bba0fdd1..1346dd2a52 100644
--- a/indra/media_plugins/cef/media_plugin_cef.cpp
+++ b/indra/media_plugins/cef/media_plugin_cef.cpp
@@ -908,6 +908,13 @@ void MediaPluginCEF::receiveMessage(const char* message_string)
             {
                 mEnableMediaPluginDebugging = message_in.getValueBoolean("enable");
             }
+#if LL_LINUX
+            else if (message_name == "enable_pipewire_volume_catcher")
+            {
+                bool enable = message_in.getValueBoolean("enable");
+                mVolumeCatcher.onEnablePipeWireVolumeCatcher(enable);
+            }
+#endif
             if (message_name == "pick_file_response")
             {
                 LLSD file_list_llsd = message_in.getValueLLSD("file_list");
diff --git a/indra/media_plugins/cef/volume_catcher.h b/indra/media_plugins/cef/volume_catcher.h
index ea97a24947..6933854e8e 100644
--- a/indra/media_plugins/cef/volume_catcher.h
+++ b/indra/media_plugins/cef/volume_catcher.h
@@ -35,19 +35,20 @@ class VolumeCatcherImpl;
 
 class VolumeCatcher
 {
- public:
+public:
     VolumeCatcher();
     ~VolumeCatcher();
 
-    void setVolume(F32 volume); // 0.0 - 1.0
-
-    // Set the left-right pan of audio sources
-    // where -1.0 = left, 0 = center, and 1.0 = right
+    void setVolume(F32 volume);
     void setPan(F32 pan);
 
-    void pump(); // call this at least a few times a second if you can - it affects how quickly we can 'catch' a new audio source and adjust its volume
+    void pump();
+
+#if LL_LINUX
+    void onEnablePipeWireVolumeCatcher(bool enable);
+#endif
 
- private:
+private:
     VolumeCatcherImpl *pimpl;
 };
 
diff --git a/indra/media_plugins/cef/mac_volume_catcher_null.cpp b/indra/media_plugins/cef/volume_catcher_null.cpp
index c479e24a95..c6028da45b 100644
--- a/indra/media_plugins/cef/mac_volume_catcher_null.cpp
+++ b/indra/media_plugins/cef/volume_catcher_null.cpp
@@ -1,5 +1,5 @@
-/**
- * @file windows_volume_catcher.cpp
+/** 
+ * @file volume_catcher_null.cpp
  * @brief A null implementation of volume level control of all audio channels opened by a process.
  *        We are using this for the macOS version for now until we can understand how to make the
  *        exitising mac_volume_catcher.cpp work without the (now, non-existant) QuickTime dependency
@@ -29,67 +29,25 @@
  */
 
 #include "volume_catcher.h"
-#include "llsingleton.h"
-class VolumeCatcherImpl : public LLSingleton<VolumeCatcherImpl>
-{
-    LLSINGLETON(VolumeCatcherImpl);
-    // This is a singleton class -- both callers and the component implementation should use getInstance() to find the instance.
-    ~VolumeCatcherImpl();
-
-public:
-
-    void setVolume(F32 volume);
-    void setPan(F32 pan);
-
-private:
-    F32     mVolume;
-    F32     mPan;
-    bool mSystemIsVistaOrHigher;
-};
-
-VolumeCatcherImpl::VolumeCatcherImpl()
-:   mVolume(1.0f),          // default volume is max
-    mPan(0.f)               // default pan is centered
-{
-}
-
-VolumeCatcherImpl::~VolumeCatcherImpl()
-{
-}
-
-void VolumeCatcherImpl::setVolume(F32 volume)
-{
-    mVolume = volume;
-}
-
-void VolumeCatcherImpl::setPan(F32 pan)
-{   // remember pan for calculating individual channel levels later
-    mPan = pan;
-}
 
 /////////////////////////////////////////////////////
 
 VolumeCatcher::VolumeCatcher()
 {
-    pimpl = VolumeCatcherImpl::getInstance();
 }
 
 VolumeCatcher::~VolumeCatcher()
 {
-    // Let the instance persist until exit.
 }
 
 void VolumeCatcher::setVolume(F32 volume)
 {
-    pimpl->setVolume(volume);
 }
 
 void VolumeCatcher::setPan(F32 pan)
 {
-    pimpl->setPan(pan);
 }
 
 void VolumeCatcher::pump()
 {
-    // No periodic tasks are necessary for this implementation.
 }
diff --git a/indra/media_plugins/cef/windows_volume_catcher.cpp b/indra/media_plugins/cef/windows_volume_catcher.cpp
index e7daeb5f74..1e52fee9de 100644
--- a/indra/media_plugins/cef/windows_volume_catcher.cpp
+++ b/indra/media_plugins/cef/windows_volume_catcher.cpp
@@ -44,7 +44,6 @@ public:
 private:
     F32     mVolume;
     F32     mPan;
-    bool mSystemIsVistaOrHigher;
 };
 
 VolumeCatcherImpl::VolumeCatcherImpl()
diff --git a/indra/media_plugins/gstreamer10/llmediaimplgstreamer_syms_raw.inc b/indra/media_plugins/gstreamer10/llmediaimplgstreamer_syms_raw.inc
index e5abf22203..6f5bb04bdf 100644
--- a/indra/media_plugins/gstreamer10/llmediaimplgstreamer_syms_raw.inc
+++ b/indra/media_plugins/gstreamer10/llmediaimplgstreamer_syms_raw.inc
@@ -1,67 +1,71 @@
-LL_GRAB_SYM(true, gst_buffer_new, GstBuffer*, void)
-LL_GRAB_SYM(true, gst_structure_set_value, void, GstStructure *, const gchar *, const GValue*)
-LL_GRAB_SYM(true, gst_init_check, gboolean, int *argc, char **argv[], GError ** err)
-LL_GRAB_SYM(true, gst_message_get_type, GType, void)
-LL_GRAB_SYM(true, gst_message_type_get_name, const gchar*, GstMessageType type)
-LL_GRAB_SYM(true, gst_message_parse_error, void, GstMessage *message, GError **gerror, gchar **debug)
-LL_GRAB_SYM(true, gst_message_parse_warning, void, GstMessage *message, GError **gerror, gchar **debug)
-LL_GRAB_SYM(true, gst_message_parse_state_changed, void, GstMessage *message, GstState *oldstate, GstState *newstate, GstState *pending)
-LL_GRAB_SYM(true, gst_element_set_state, GstStateChangeReturn, GstElement *element, GstState state)
-LL_GRAB_SYM(true, gst_object_unref, void, gpointer object)
-LL_GRAB_SYM(true, gst_object_get_type, GType, void)
-LL_GRAB_SYM(true, gst_pipeline_get_type, GType, void)
-LL_GRAB_SYM(true, gst_pipeline_get_bus, GstBus*, GstPipeline *pipeline)
-LL_GRAB_SYM(true, gst_bus_add_watch, guint, GstBus * bus, GstBusFunc func, gpointer user_data)
-LL_GRAB_SYM(true, gst_element_factory_make, GstElement*, const gchar *factoryname, const gchar *name)
-LL_GRAB_SYM(true, gst_element_get_type, GType, void)
-LL_GRAB_SYM(true, gst_static_pad_template_get, GstPadTemplate*, GstStaticPadTemplate *pad_template)
-LL_GRAB_SYM(true, gst_element_class_add_pad_template, void, GstElementClass *klass, GstPadTemplate *temp)
-LL_GRAB_SYM(true, gst_caps_from_string, GstCaps *, const gchar *string)
-LL_GRAB_SYM(true, gst_caps_get_structure, GstStructure *, const GstCaps *caps, guint index)
-LL_GRAB_SYM(true, gst_element_register, gboolean, GstPlugin *plugin, const gchar *name, guint rank, GType type)
-LL_GRAB_SYM(true, gst_structure_get_int, gboolean, const GstStructure *structure, const gchar *fieldname, gint *value)
-LL_GRAB_SYM(true, gst_structure_get_value, const GValue *, const GstStructure *structure, const gchar *fieldname)
-LL_GRAB_SYM(true, gst_value_get_fraction_numerator, gint, const GValue *value)
-LL_GRAB_SYM(true, gst_value_get_fraction_denominator, gint, const GValue *value)
-LL_GRAB_SYM(true, gst_structure_get_name, const gchar *, const GstStructure *structure)
-LL_GRAB_SYM(true, gst_element_seek, bool, GstElement *, gdouble, GstFormat, GstSeekFlags, GstSeekType, gint64, GstSeekType, gint64)
+#define G gstSymbolGrabber
 
-LL_GRAB_SYM(false, gst_registry_fork_set_enabled, void, gboolean enabled)
-LL_GRAB_SYM(false, gst_segtrap_set_enabled, void, gboolean enabled)
-LL_GRAB_SYM(false, gst_message_parse_buffering, void, GstMessage *message, gint *percent)
-LL_GRAB_SYM(false, gst_message_parse_info, void, GstMessage *message, GError **gerror, gchar **debug)
-LL_GRAB_SYM(false, gst_element_query_position, gboolean, GstElement *element, GstFormat *format, gint64 *cur)
-LL_GRAB_SYM(false, gst_version, void, guint *major, guint *minor, guint *micro, guint *nano)
+LL_GRAB_SYM(G, true, gst_buffer_new, GstBuffer*, void)
+LL_GRAB_SYM(G, true, gst_structure_set_value, void, GstStructure *, const gchar *, const GValue*)
+LL_GRAB_SYM(G, true, gst_init_check, gboolean, int *argc, char **argv[], GError ** err)
+LL_GRAB_SYM(G, true, gst_message_get_type, GType, void)
+LL_GRAB_SYM(G, true, gst_message_type_get_name, const gchar*, GstMessageType type)
+LL_GRAB_SYM(G, true, gst_message_parse_error, void, GstMessage *message, GError **gerror, gchar **debug)
+LL_GRAB_SYM(G, true, gst_message_parse_warning, void, GstMessage *message, GError **gerror, gchar **debug)
+LL_GRAB_SYM(G, true, gst_message_parse_state_changed, void, GstMessage *message, GstState *oldstate, GstState *newstate, GstState *pending)
+LL_GRAB_SYM(G, true, gst_element_set_state, GstStateChangeReturn, GstElement *element, GstState state)
+LL_GRAB_SYM(G, true, gst_object_unref, void, gpointer object)
+LL_GRAB_SYM(G, true, gst_object_get_type, GType, void)
+LL_GRAB_SYM(G, true, gst_pipeline_get_type, GType, void)
+LL_GRAB_SYM(G, true, gst_pipeline_get_bus, GstBus*, GstPipeline *pipeline)
+LL_GRAB_SYM(G, true, gst_bus_add_watch, guint, GstBus * bus, GstBusFunc func, gpointer user_data)
+LL_GRAB_SYM(G, true, gst_element_factory_make, GstElement*, const gchar *factoryname, const gchar *name)
+LL_GRAB_SYM(G, true, gst_element_get_type, GType, void)
+LL_GRAB_SYM(G, true, gst_static_pad_template_get, GstPadTemplate*, GstStaticPadTemplate *pad_template)
+LL_GRAB_SYM(G, true, gst_element_class_add_pad_template, void, GstElementClass *klass, GstPadTemplate *temp)
+LL_GRAB_SYM(G, true, gst_caps_from_string, GstCaps *, const gchar *string)
+LL_GRAB_SYM(G, true, gst_caps_get_structure, GstStructure *, const GstCaps *caps, guint index)
+LL_GRAB_SYM(G, true, gst_element_register, gboolean, GstPlugin *plugin, const gchar *name, guint rank, GType type)
+LL_GRAB_SYM(G, true, gst_structure_get_int, gboolean, const GstStructure *structure, const gchar *fieldname, gint *value)
+LL_GRAB_SYM(G, true, gst_structure_get_value, const GValue *, const GstStructure *structure, const gchar *fieldname)
+LL_GRAB_SYM(G, true, gst_value_get_fraction_numerator, gint, const GValue *value)
+LL_GRAB_SYM(G, true, gst_value_get_fraction_denominator, gint, const GValue *value)
+LL_GRAB_SYM(G, true, gst_structure_get_name, const gchar *, const GstStructure *structure)
+LL_GRAB_SYM(G, true, gst_element_seek, bool, GstElement *, gdouble, GstFormat, GstSeekFlags, GstSeekType, gint64, GstSeekType, gint64)
 
-LL_GRAB_SYM( true, gst_message_parse_tag, void, GstMessage *, GstTagList **)
-LL_GRAB_SYM( true, gst_tag_list_foreach, void, const GstTagList *, GstTagForeachFunc, gpointer)
-LL_GRAB_SYM( true, gst_tag_list_get_tag_size, guint, const GstTagList *, const gchar *)
-LL_GRAB_SYM( true, gst_tag_list_get_value_index, const GValue *, const GstTagList *, const gchar *, guint)
+LL_GRAB_SYM(G, false, gst_registry_fork_set_enabled, void, gboolean enabled)
+LL_GRAB_SYM(G, false, gst_segtrap_set_enabled, void, gboolean enabled)
+LL_GRAB_SYM(G, false, gst_message_parse_buffering, void, GstMessage *message, gint *percent)
+LL_GRAB_SYM(G, false, gst_message_parse_info, void, GstMessage *message, GError **gerror, gchar **debug)
+LL_GRAB_SYM(G, false, gst_element_query_position, gboolean, GstElement *element, GstFormat *format, gint64 *cur)
+LL_GRAB_SYM(G, false, gst_version, void, guint *major, guint *minor, guint *micro, guint *nano)
 
-LL_GRAB_SYM( true, gst_caps_new_simple, GstCaps*, const char *, const char*, ... )
+LL_GRAB_SYM(G, true, gst_message_parse_tag, void, GstMessage *, GstTagList **)
+LL_GRAB_SYM(G, true, gst_tag_list_foreach, void, const GstTagList *, GstTagForeachFunc, gpointer)
+LL_GRAB_SYM(G, true, gst_tag_list_get_tag_size, guint, const GstTagList *, const gchar *)
+LL_GRAB_SYM(G, true, gst_tag_list_get_value_index, const GValue *, const GstTagList *, const gchar *, guint)
 
-LL_GRAB_SYM( true, gst_sample_get_caps, GstCaps*, GstSample* )
-LL_GRAB_SYM( true, gst_sample_get_buffer, GstBuffer*, GstSample* )
-LL_GRAB_SYM( true, gst_buffer_map, gboolean, GstBuffer*, GstMapInfo*, GstMapFlags )
-LL_GRAB_SYM( true, gst_buffer_unmap, void, GstBuffer*, GstMapInfo* )
+LL_GRAB_SYM(G, true, gst_caps_new_simple, GstCaps*, const char *, const char*, ... )
 
-LL_GRAB_SYM( true, gst_app_sink_set_caps, void, GstAppSink*, GstCaps const* )
-LL_GRAB_SYM( true, gst_app_sink_pull_sample, GstSample*, GstAppSink* )
+LL_GRAB_SYM(G, true, gst_sample_get_caps, GstCaps*, GstSample* )
+LL_GRAB_SYM(G, true, gst_sample_get_buffer, GstBuffer*, GstSample* )
+LL_GRAB_SYM(G, true, gst_buffer_map, gboolean, GstBuffer*, GstMapInfo*, GstMapFlags )
+LL_GRAB_SYM(G, true, gst_buffer_unmap, void, GstBuffer*, GstMapInfo* )
 
-LL_GRAB_SYM( true, g_free, void, gpointer )
-LL_GRAB_SYM( true, g_error_free, void, GError* )
+LL_GRAB_SYM(G, true, gst_app_sink_set_caps, void, GstAppSink*, GstCaps const* )
+LL_GRAB_SYM(G, true, gst_app_sink_pull_sample, GstSample*, GstAppSink* )
 
-LL_GRAB_SYM( true, g_main_context_pending, gboolean, GMainContext* )
-LL_GRAB_SYM( true, g_main_loop_get_context, GMainContext*, GMainLoop* )
-LL_GRAB_SYM( true, g_main_context_iteration, gboolean, GMainContext*, gboolean )
-LL_GRAB_SYM( true, g_main_loop_new, GMainLoop*, GMainContext*, gboolean )
-LL_GRAB_SYM( true, g_main_loop_quit, void, GMainLoop* )
-LL_GRAB_SYM( true, gst_mini_object_unref, void, GstMiniObject* )
-LL_GRAB_SYM( true, g_object_set, void, gpointer, gchar const*, ... )
-LL_GRAB_SYM( true, g_source_remove, gboolean, guint )
-LL_GRAB_SYM( true, g_value_get_string, gchar const*, GValue const* )
+LL_GRAB_SYM(G, true, g_free, void, gpointer )
+LL_GRAB_SYM(G, true, g_error_free, void, GError* )
 
-LL_GRAB_SYM( true, gst_debug_set_active, void, gboolean )
-LL_GRAB_SYM( true, gst_debug_add_log_function, void, GstLogFunction, gpointer, GDestroyNotify )
-LL_GRAB_SYM( true, gst_debug_set_default_threshold, void, GstDebugLevel )
-LL_GRAB_SYM( true, gst_debug_message_get , gchar const*, GstDebugMessage * )
\ No newline at end of file
+LL_GRAB_SYM(G, true, g_main_context_pending, gboolean, GMainContext* )
+LL_GRAB_SYM(G, true, g_main_loop_get_context, GMainContext*, GMainLoop* )
+LL_GRAB_SYM(G, true, g_main_context_iteration, gboolean, GMainContext*, gboolean )
+LL_GRAB_SYM(G, true, g_main_loop_new, GMainLoop*, GMainContext*, gboolean )
+LL_GRAB_SYM(G, true, g_main_loop_quit, void, GMainLoop* )
+LL_GRAB_SYM(G, true, gst_mini_object_unref, void, GstMiniObject* )
+LL_GRAB_SYM(G, true, g_object_set, void, gpointer, gchar const*, ... )
+LL_GRAB_SYM(G, true, g_source_remove, gboolean, guint )
+LL_GRAB_SYM(G, true, g_value_get_string, gchar const*, GValue const* )
+
+LL_GRAB_SYM(G, true, gst_debug_set_active, void, gboolean )
+LL_GRAB_SYM(G, true, gst_debug_add_log_function, void, GstLogFunction, gpointer, GDestroyNotify )
+LL_GRAB_SYM(G, true, gst_debug_set_default_threshold, void, GstDebugLevel )
+LL_GRAB_SYM(G, true, gst_debug_message_get , gchar const*, GstDebugMessage * )
+
+#undef G
diff --git a/indra/media_plugins/gstreamer10/media_plugin_gstreamer10.cpp b/indra/media_plugins/gstreamer10/media_plugin_gstreamer10.cpp
index dbc544d96b..3f636915ea 100644
--- a/indra/media_plugins/gstreamer10/media_plugin_gstreamer10.cpp
+++ b/indra/media_plugins/gstreamer10/media_plugin_gstreamer10.cpp
@@ -41,9 +41,9 @@
 extern "C" {
 #include <gst/gst.h>
 #include <gst/app/gstappsink.h>
-
 }
-SymbolGrabber gSymbolGrabber;
+
+SymbolGrabber gstSymbolGrabber;
 
 #include "llmediaimplgstreamer_syms_raw.inc"
 
@@ -650,7 +650,7 @@ bool MediaPluginGStreamer10::startup()
         vctDSONames.push_back( "libgstapp-1.0.so.0"  );
         vctDSONames.push_back( "libglib-2.0.so.0" );
         vctDSONames.push_back( "libgobject-2.0.so" );
-        if( !gSymbolGrabber.grabSymbols( vctDSONames ) )
+        if( !gstSymbolGrabber.grabSymbols( vctDSONames ) )
             return false;
 
         if (llgst_segtrap_set_enabled)
@@ -712,7 +712,7 @@ bool MediaPluginGStreamer10::closedown()
     if (!mDoneInit)
         return false; // error
 
-    gSymbolGrabber.ungrabSymbols();
+    gstSymbolGrabber.ungrabSymbols();
     mDoneInit = false;
 
     return true;